000
AXPZ20 KNHC 202145
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SAT DEC 20 2014

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS W FROM THE PACIFIC COAST OF COLOMBIA 
AT 07N78W TO 06N92W WHERE SCATTEROMETER WINDS INDICATE A 
TRANSITION TO AN ITCZ WHICH CONTINUES WNW TO A 1011 MB EMBEDDED 
LOW PRESSURE AT 08N101W TO 05N140W...THEN CONTINUES WSW TO 
BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
OBSERVED ALONG THE MONSOON TROUGH WITHIN 90 NM OF 05N80W. 
SCATTERED MODERATE ISOLATED STRONG OBSERVED NEAR THE EMBEDDED 
LOW PRESSURE WITHIN 90 NM EITHER SIDE OF A LINE FROM 07N97W TO 
09N101W TO 05N113W. SCATTERED MODERATE WITHIN 30 NM EITHER SIDE 
OF A LINE OF LINE FROM 07N123W TO 07N130W. 

...DISCUSSION...                                                 

AN UPPER LEVEL TROUGH EXTENDS FROM 32N106W TO 16N125W. DENSE  
UPPER MOISTURE IS SPREADING SE ACROSS THE DISCUSSION AREA TO THE 
N OF 27N BETWEEN 110-124W. A PLUME OF UPPER MOISTURE... 
ORIGINATING FROM ITCZ CONVECTION BETWEEN 138-160W...CONTINUES TO 
STREAM NE ACROSS THE DISCUSSION AREA WITHIN 300 NM EITHER SIDE 
OF A LINE FROM 10N120W TO OVER THE PACIFIC COAST OF MEXICO AT 
10N105W...THEN NARROWS AS IT CONTINUES NE ACROSS CENTRAL 
MEXICO...TURNING ENE ACROSS THE GULF OF MEXICO AND ACROSS 
CENTRAL FLORIDA.

AT THE LOW LEVELS...LONG PERIOD NW SWELL CONTINUES PROPAGATE E 
ACROSS THE ENTIRE OPEN WATERS WATERS N OF THE ITCZ W OF ABOUT 
115W...RESULTING IN COMBINED SEAS OF 8-16 FT...WITH THE HIGHEST 
SEAS NEAR 30N125W. THIS LONG PERIOD NW SWELL WILL ARRIVE ALONG 
THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA IN THE FORM OF 
8-13 FT SEAS TONIGHT THEN DIMINISH SOME...WITH 7-10 FT SEAS 
EXPECTED ALONG THE ENTIRE PACIFIC COAST OF THE BAJA PENINSULA ON 
SUN. THE SWELLS WILL SUBSIDE WITH 6-8 FT CONDITIONS EXPECTED 
ALONG THE ENTIRE PACIFIC COAST OF THE BAJA PENINSULA ON MON AND 
MON NIGHT...THEN SUBSIDE TO 4-7 FT ON TUE ACROSS THE COASTAL 
WATERS S OF 28N. GUIDANCE IS SUGGESTING THE NORTHERLY FLOW WILL 
INCREASE TO 20-25 KT...SEAS 8-11 FT...ACROSS THE DISCUSSION 
WATERS N OF 28N BETWEEN 120-128W ON MON NIGHT...THEN DIMINISH TO 
15-20 KT ON TUE. GUIDANCE IS ALSO SUGGESTING NE WINDS WILL 
INCREASE TO 20-25 KT ALONG THE PACIFIC COAST OF THE BAJA 
PENINSULA AT 29N ON TUE...THEN SPREAD SW TO NE 27N117W ON TUE 
NIGHT BEFORE DIMINISHING ON WED.     

A SURFACE RIDGE EXTENDS FROM 31N136W TO 15N105W. NE 15-20 KT 
TRADES ARE OBSERVED ACROSS THE TROPICS BETWEEN THE ITCZ AND THE 
RIDGE WITH AN AREA OF EMBEDDED 20-25 KT NE WINDS ACROSS THE 
WATERS FROM 07-22N W OF 120W. THE GRADIENT SHOULD BEGIN TO 
WEAKEN ON MON WITH THE AREA OF 20-25 KT CONDITIONS SHRINKING 
THROUGH MON...AND DIMINISHED BELOW 20 KT ACROSS THE DISCUSSION 
WATERS ON TUE. THE COMBINED SEAS WILL CONTINUE TO SUBSIDE TO THE 
7-9 FT RANGE ACROSS THE PACIFIC WATERS W OF 115W ON THU.  

GULF OF TEHUANTEPEC...EXPECTING A MAX OF 15-20 KT NOCTURNAL  
DRAINAGE FLOW ACROSS THE GULF OF TEHUANTEPEC TONIGHT AND 10-15 
KT ON SUN NIGHT. MODEL GUIDANCE SUGGESTS THE DRAINAGE FLOW WILL 
INCREASE TO 20-25 KT LATE TUE NIGHT...THEN RAPIDLY INCREASE TO 
GALE FORCE WED AFTERNOON...AND FURTHER INCREASE TO NEAR STORM 
STRENGTH LATE WED NIGHT. EXPECT THE GALE EVENT TO END ON THU 
NIGHT. 
   
GULF OF PAPAGAYO...NE 15-20 KT NOCTURNAL PULSES EXPECTED THROUGH 
EARLY MON...THEN ONLY 10-15 KT DRAINAGE FLOW MON AND TUE NIGHTS. 
GUIDANCE SUGGESTS 20-25 KT CONDITIONS WILL BEGIN LATE WED 
NIGHT...WITH A SIGNIFICANT EVENT OF 20-30 KT WINDS LATE THU 
NIGHT. 
 
GULF OF CALIFORNIA...15-20 KT NW WINDS ARE EXPECTED THROUGH SUN 
NIGHT THEN DIMINISH TO 10-15 KT ON MON AND MON NIGHT. THE 
GRADIENT WILL TIGHTEN EARLY TUE WITH THE NW FLOW INCREASING TO 
20-25 KT ACROSS THE NORTHERN GULF WATERS EARLY TUE...WITH THESE 
CONDITIONS SPREADING S ACROSS THE ENTIRE GULF OF CALIFORNIA BY 
TUE EVENING. THE GRADIENT SHOULD RELAX ON WED. 
 
$$
NELSON